1. Field of the Disclosure
This disclosure relates generally to a completion system wherein a production string for the production of hydrocarbons may include an expandable control line.
2. Background of the Art
Wells or wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Modern wells can extend to great well depths, sometimes more than 8,000 meters (over 25,000 ft.). Hydrocarbons are trapped in various traps in the subsurface formations at different depths. The areas of the formation that contain the hydrocarbons are referred to as reservoirs or hydrocarbon-bearing formations or production zones. The wellbore is lined with a casing and the annulus between the casing and the wellbore is filled with cement. Perforations are made through the casing and the formation to allow the hydrocarbons to flow from the production zones into the wellbore. A production string is placed inside the casing to lift the hydrocarbons from the wellbore to the surface. The production string for deep wells can include a tubing from the surface that exceeds 5,000 meters (over 15,000 feet). Expansion joints have been used to accommodate for the expansion and contraction of the tubing during deployment and for the expansion during the life of the production string. A control line is generally run from a surface location to the various production zones, with control line coiled around a tubular in the expansion joint. For deep wells, the expansion joint may exceed 120 feet and thus the control line will have numerous coils placed around the expansion joint. In deep wells, several control lines may be required, such as 3-5 control lines that are coiled or passed over the expansion joint with a long stroke, such as 120 feet. In such a case, the control lines may be fully or mostly stretched during deployment. After deployment, the expansion joint length is reduced, which causes the coils at a bottom section the coils to compress, while leaving coils in the upper section stretched. The stretch for the uppermost coil is the greatest and it bears the entire weight of the unstretched section of the coils. Strings, such as production strings, expand and contract over the life of the well, which causes the expansion joint to stretch and compress, thereby stretching and compressing the coils. The coils do not stretch uniformly. Also, once a coil is stretched excessively, either during deployment of thereafter, it may not retract back to its original shape due to the yielding of the coil material, which material may be a metal or an alloy. Stretching of the coiled control line will cause an upper point in a particular coil to lift the weight of the coils stretched below that coil, which weight may be excessive, at least for the coils in the upper section of the coiled control line. Such excessive weight on the coils may be detrimental to control line and in may damage the control line. Also, the amount of the stretch of the coils differs. For example, the top coil of the coiled control line will stretch first to a certain distance before the next lower coil will start to stretch and so forth, thereby providing uneven stretching of the coils.
The disclosure herein provides a completion system wherein a production string includes an expansion joint with a coiled control line wherein stretch of at least some of the coil is limited or controlled.